I have a metallic hiss coming from the rear of my 1972 BMW 2002. It has been doing this for a year without affecting performance but it is irritating. It sounds as though two smooth circular plates are rubbing and it changes character slightly from acceleration to deceleration, but is constant unless it is wet out, in which case it lessens. Any ideas?

Author: Duffy Williams
Monona, Wisconsin

This is most likely due to worn or cracked rear support bearings. The sound lessens when the road surface is wet because the water thrown up lubricates the rubber. Check the metal tensioning arm first to see if it is cracked or bent. The bearings cost about $15 each, the rear seat has to be removed to replace them, and it will help a lot if-you have a hydraulic jack when you go to replace them. Tech Ed.